[armchairhacker]

Or it could be short-term relief that moves somebody from a bad mindset to a good one, so they start taking care of themselves. Perhaps it makes them go out more, leading to real friends.

The key is "good". An AI friend which just validates and reinforces one's existing feelings (like current AI) may become popular, but I wouldn't call it a good friend. Fortunately if such AI leads to bad outcomes, real friendship will be seen as more valuable.